Steam-boiler.



No. 630,560. Y Patented Aug. 8, I899.

C. C. PEGK.

STEAM BOILER.

(Application filed Apr. 25. 1898.) No Model.)

4' Sheets-Sheet l.

m INVENTEIR:

Patented Aug. 8, I899. C. C. PECK. STEAM BOILER.

(Application filed Apr. 25, 1898.) No Model.)

4 SheetsSheet 2.

WiT E5555:

No. 630,560. Patented Aug. 8, I899.

.C. C. PEEK.

STEAM BOILER.

Application filed Apr. 25, 1898.)

';No Model.) 4 Sheets-Sheet 3.

ll H 0 $000000 WiTNEBEl-IE! No. 630,560. Patented Aug. 8, I899. C. C. PECK.

STEAM BOILER.

{Application filed Apr. 25, 1898.) (No Model.) '4 Sheets-Sheet 4.

UNITED. STATES PATENT OFFICE.

CASSIUS CARROLL PECK, OF ROCHESTER, NEW YORK.

STEAM-BOILER.

SPECIFICATION forming part of Letters Patent No. 630,560, dated August 8, 1899.

Application filed April 25, 1898. gerifll NO- 1 (N0 o To all whom it may concern:

Be it known that LOAssIUs CARROLL PEoK,

residing at Rochester, inthe county of Mon} nally-fired boilers and to boilers having'in ternal furnaces.

The main object of my invention is to im-' prove boiler efficiency; but it also includes the attainment of good proportions for waterspace,steam-space,and water-separating surface for steam, whereby, easy action of the boiler, good reserve power, and dry steam are providedfor. Another object sought and secured is reduction in the size of shell required for any given power and capacity. by dividing'the total amount of power for a boiler into two shells and giving to each shell a similar amount of tube area and a properly corresponding amount of heating-surface. The use of two shells also results in durable conditions of the boiler structure when in use and in convenience and ease in cleaning. As com-.

pared with ordinary sin gle-shell boilers it also effects reduction in cost in the case of large boiler plants, especially where high steampressures are required, as well as a large reduction in the floor area needed for setting.

In the accompanying drawings, Figure I is a front end elevation of an externally-fired boiler,showing one half of the castings of fluedoors and furnace-front, together with brickwork, ,the other half of drawing showing said fronts removed to reveal one-half of the boiler-head and a cross-section of brickwork of side wall. Fig. II is a lengthwise vertical central section of same boiler with brickwork-setting. Fig. 111 is a front end elevation of 'a boiler with internal furnaces, showing on one side of the vertical central line one of the furnace-fronts and one fluedoor of both the lower and the upper shell and on the other side of said line one-half the front head of both the lower and the upper shell.

Fig. IV is a lengthwise vertical section of 'same boiler. I A and B are two boiler shells connected by a neck 0, having steam-pipes c for conveying steam generated in the primary boiler A in to the steam-space of the secondary boiler B, andwater-pipes e. for delivering overflow- }water from boiler B into the water-space of boiler A. Each boiler has about the same number of tubes at and b, and boiler B has a dry pipe'b, a steam-pipe flange b safetyvalve flanges b and a feed-pipe b. Each of the boilers has a blow-off flange a," and 19 At the front end each boiler has a smoke-box A and B, formed by anextensiou of each boilershell, and the two smoke-boxes are connected by a neck C. At the rear end of boiler B is another smoke-box Biformed by the extension of the boiler-shell, the upper shell having a smoke-pipe 'collarb Arrows feathered on both sidesshow course of fire-cases, those feathered on only one side show course taken by steam, and nnfeathered arrows indicate the movement of water.

The operation of'the boiler'is as follows:

Fire being started in furnaceD, the gases and smoke are drawn by chimney or mechanical draft either under the shell in case of the externally-flred boiler (shown in Figs. land 11) or through the furnace-flue d of the internallyfired boiler v(shown in Figs. IlI'and IV) and on reaching and passing through to rear end of combustion chamber D enter and pass through the fire-tubes a in the lower shell A to the front end smoke-box A, where they pass through smoke-neck O to smoke-box B and through fire-tubes b in upper shell B to rear smoke-box B escaping through smoke connection I) to the smoke-stack or to the inducing-fan, as the case may be. Feed-water being supplied through pipe 12 until the shell is filled to the water-level at H, and being continued for the purpose of supplying boiler A', the water overflows through pipes 0 into the water-space of shell A. The feed-water being delivered at the rear end of shell B becomes gradually heated to steam temperature in flowing toward the point of overflow at front end of the shell, while the gases which move through fire-tubes b in opposite direction to the movement of water are cooled to the lowest possible point before escape to chimney. The feed-water in its slow movement through shell 13 parts with more or less of solid matter contained in suspension and solution, this matter either settling directly to the bottom of the shell or first rising to the top of the water as scum. To prevent such scum from overflowing into boiler A, the overflow-pipes c are returned under the waterlevel, as shown in dotted lines, Fl II, in case the water is of such a nature as to form scum. The level of water in boiler 13 does not require watching, as it cannot get higherthan permitted by pipes c, and as evaporation is always most rapid in boilerA the water-level in boiler B must be constantly kept close to the overflow-point in order to have boiler A supplied. It is therefore necessary to watch the waterlevel in boiler A only and pump or otherwise force feed-water into shell B only as required to replace evaporation in shell A. As water enters the latter at steam temperature and mostly freed from solid matter, it is in best condition for evaporation and boiler A performs only the duty of evaporating, while boiler I3 includes the functions of heater, purifier, and cconomizer together with that of boiler.

As fast as steam is produced in boiler A it passes by pipes 0 into boiler B, mingling with steam produced in the latter, and is thence taken for use through a steam-pipe connected to flange b asshown in Figs. I and IV. A dry pipe Z) is not usually needed, butmay be used for drawing steam in a uniform manner from the rear end of boiler. The pipes c are preferably made of sufficient length to cause the steam to impinge against the surface of shell B, which thereby acts as a separator for catching any entrained water coming over from boiler A. A valuable feature of this arrangement of two boiler-shells is that much solid matter is prevented from entering boiler-A, the shell of which is subjected to direct action of the fire and the tubes of which are in contact with the hottest gases. This condition requires less time and trouble in cleaning than in ordinary return tubular boilers and promotes ellicieney of the heating-surfaces, and by guarding against overheating tends to make the boiler more safe and durable. In the case of the common occurrence of getting oil into feedwater through use of open heaters boiler B acts as an efficient trap for boiler A, while the temperatures of gases in contact with the latter are not suiliciently high to cause serious injury even if the heatingsurfaces become coated with oil. The shell of boiler A is also protected, and the efficiency of the heating surfaces of shell and tubes is greater than in ordinary return tubular boilers because of more rapid and uniform circulation where all the water is in a state of boiling, and the shell is thus best preserved from strains caused by unequal contraction and expansion, these being severe and dangerous in the case of ordinary boilers set directly over the fire into which cold or cool water is pumped. In case of shell B,'into which the feed-water is delivered, the shell is not in contact with the fire or. gases, and the temperatures acting on the tubes are too low to allow of variations sufficient to cause excessive strains.

In width of floor-space occupied this boiler requires only that necessary for grate-surface. In large boiler plants the floor-space required is only about half that needed for ordinary return tubularboilers.

Another valuable feature in the design of this boiler is that with the same thickness of metal it is much stronger than ordinary return tubular boilers made with a single shell because the necessary amount of heatingsurface for agiven amount of power is divided nearly equally between two shells, which are consequently of much smaller diameter. This better adapts it for use in large units and for high pressures.

In setting up the boiler all steam-heated surfaces are covered to prevent loss of heat and the flue-doors at the front end of boiler A and boiler 13 are lined with non-heat-conducting material to prevent loss of heat from the fire-gases.

Under some conditions it might be desirable to feed boiler 13 in a somewhat diifercnt manner from that shown. I do not, therefore, intend to confine myself strictly to the arrangement of feed pipe shown. Neither do I adhere strictly to the manner of connecting the steam and water spaces shown and described, as equivalent pipes earried outside the two boiler-shells will answer the same purpose, although such pipes would require covering and would not constitute so compact an arrangement as that shown.

It is not necessary that the boiler 13 shall be set directly above boiler A. Thus in locations where head-room will not admit of placing boiler B immediately above boilerA the former may be set more or less to one side without materially affecting the operation, so long as the water-level in boiler 3 is kept above the water-level in boiler A.

\Vhat I claim as my invention, and desire to secure by Letters Patent, is

l. A return tubular boiler consisting of two shells each of which has a separate and independent water-level and each having a set of fire-tubes with sufficient sectional area for conveying the gases produced in the furnace when operating the boiler at rating, with a proper margin above rating, the tubes in both shells being of proper length to give conjointly the necessary boiler-heating surface for developing the horse-power rating of the boiler, the steam-space in the two shells be ing connected by one or more pipes so as to equalize pressure in the two shells, and the water-space in the two shells being also connected by one or more pipes so that the water-space in the lower of the two shells will be supplied by overflow from the water-space in the upper shell, the two shells being so constructed and set that the fire-gases must pass successively through the tubes in the lower shell and then through the tubes in the upper shell, in their course from furnace to chimney, substantially as, and for the pur: pose, described.

2. The combination with a return tubular boiler composed of two shells, each of which contains fire-tubes of sufficient cross-sectional area for the passage of fire-gases from furnace to chimney, and each of which has its own independent water level, the steamspaces of the two shells being connected and the water-space of the lower shell supplied from the water-space of the upper shell, of the two smoke-loo xes connected by the smokeneck, substantially as shown and described.

3. The combination of a return tubular boiler composed of two shells, each of which contains fire-tubes having sufficient crosssectional area for the passage of fire-gases from furnace to chimney and a separate water-level for each shell, the two shells having each a smoke-box at the end connected by a smoke-neck so that the gases must pass successively through the tubes in the lower shell and in the upper shell to neck 0, having steam-pipes c for connecting the steam-space in the lower shell with the steam-space in the upper shell, and the water-pipes c for conveying overflow of water in the upper shell to the water-spacein lower shell, all substantially as shown and for the purpose described.

4. The combination of a return tubular boiler composed of two shells, each of which contains fire-tubes of sufficient cross-sectional area for passage of the fire-gases from furnace to chimney, and each of which have their steam-spaces connected, and their waterspaces so arranged and connected that the water-spaces of the primary-boiler shell shall be supplied from the water-space of the secondary-boiler shell which first receives the feed-water, the two shells being provided with a smoke-box at the front end of each connected together by a neck in manner substantially as shown, and the rear extension of shell B to form a smoke-box Bisubstantially as shown and for the purpose described.

5. The combination with a return tubular steam-space connected with the steam-space in the other shell, and the water-space in each so arranged and connected that the waterspace of the primary boiler A shall be supplied from the water-space of secondary boiler B, and the feed-pipe I) located at the opposite end of shell B from which the fire-gases enter the tubes of said shell, and at the opposite end from which water is taken for supplying the water-space in primary boiler A, for the object described.

6. In a return'tubular boiler composed of two shells, each of which contains fire-tubes of sufficient cross-sectional area for passage of fire-gases from furnace to chimney, and the two shells being so connected that the gases traverse successively the tubes in each shell, and the steam-space in each shell connected with the steam-space in the other shell, the arrangement and combination of feed-pipe b and overflow-pipe c,whereby the water-space of boiler A receives its supply through overflow from boiler B, for the object set forth.

7. In combination with a return tubular boiler composed of two shells, each of which contains fire-tubes'of sufficient cross-sectional area for passage of fire-gases from furnace to chimney, the shells being so connected that the gases traverse successively the tubes in each shell, the steam-space in each shell being connected with the steam-space in the other shell, and the water-space in each so arranged and connected that the water-space of the primary boiler A shall be supplied from the Water-space of secondary boiler B, the steam-pipes c and steam-supply-pipe flange b so arranged that steam drawn from the shell A must enter and pass through the shell B, substantially as shown and for the purpose described.

CASSIUS CARROLL PEOK. Witnesses:

D. W. GARDNER, FLORENCE MIATT. 

